Distortionable chamber low leakage pump



Nov. 12 1968 w. H. SHOPE DISTORTIONABLE CHAMBER LOW LEAKAGE PUMP Filed April 17, 1967 II(I(IIIIIIIIIAV IIII I VEN TOR [Mm H S/wpe ATTORNEY United States Patent 3,410,219 DISTORTIONABLE CHAMBER LOW LEAKAGE PUMP William H. Shope, Phoenix, Ariz., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Apr. 17, 1967, Ser. No. 631,405 6 Claims. (Cl. 103149) ABSTRACT OF THE DISCLOSURE A rotary pump having an annular series of multiple pumping chambers separated by flexible elastomeric webs, the chambers being arranged to be sequentially distorted or constricted sufiiciently by an eccentrically held porting shaft to give an inflow and discharge of fluid through the shaft.

This invention relates to pumps and more particularly to pumps in which pressure and discharge of fluid is effected by sequential distortion of a series of flexible wall chambers.

Distortionable chamber pumps have been known but difiiculties of porting and/ or valving have often been met with in their use. A satisfactory pump of the type referred to is disclosed in the United States Patent 2,882,830, granted Apr. 21, 1959, but in the use of this patented structure a spring and a fluid differential pressure must be employed in order to combat possible leakage between the relatively movable parts.

An object of the present invention is to provide an improved distortionable chamber type pump of simplified construction and which will be characterized by a minimum of leakage between relatively movable parts.

To this end, a feature of the invention is a pump having a chambered body member with flexible or elastomeric vanes and the pump being ported for fluid flow independent of the use of fluid pressure or a spring for effecting sealing.

This and other important features of the invention will now be described in detail and also pointed out more particularly in the appended claims.

In the drawing:

FIGURE 1 is a sectional view through one embodiment of the present invention;

FIGURE 2 is a sectional view looking in the direction of the arrows 22 in FIGURE 1; and

FIGURE 3 is a perspective view, with a portion broken away of an elastomeric and chambered part of the pump shown in FIGURES l and 2.

FIGURE 1 depicts a drive shaft 10 and a ported shaft 12 arranged in parallel relation and with opposing ends terminating close to each other. The drive shaft 10 has a pump body 14 fixed to rotate with it as an integral unit. The pump body 14 includes an end plate 16 joined to a rim of a cup-like part 18 and the latter bears an aperture 20 through which the shaft 12 extends. The plate 16 and part 18 may be of steel or of rigid plastic.

A flexible elastomeric member 22 is retained within the cap 18 and bonded thereto as well as to the plate 16. The member 22 includes integral and flexible webs 24 passing radially from a hub portion 26 to the peripheral portion 28. The elastomeric member also includes an integral annular base 30 bonded to the bottom of the part or cup 18. Edges of the webs 24 flush with the surface of plate 16 are bonded to the latter so that four separate chambers 32 are defined by the elastomeric member and the plate 16 and separated by the webs 24. Four arcuate and flanged plates 34 are bonded to the base 30 of the member 22 so that each aids in maintaining the integrity of one of the chambers 32. A circular plate 36 with an annular flange 38 thereon is fixed to and coaxial with the plate 16 and the shaft 10 and the flange 38 is bonded to the hub portion 26 of the elastomeric member.

The shaft 12 is made with two bores 40 and 42 and each of these is closed at one end of the shaft 12 by means of a threaded screw such as the screw 44. The bores 40 and 42 are provided with oppositely facing slots 46 and 48 respectively and in the same radial plane of these slots are located four equally spaced ports 50 in a bushing 52. The latter is bonded as at 54 to the hub portion 26 of the elastomeric member 22. An aperture 56 is made in the hub portion 26 to register with each of the ports 50.

In operation of the pump, and it being assumed that the shaft 10 is a drive shaft, ported shaft 12 will be held fixed in position but the offset relation of the shaft axes will cause the chambers 32 in the elastomeric member 22 to be sufliciently and sequentially restricted and expanded whereby a flow of fluid through one of the ports 40 or 42 into the pump and an outflow of fluid through the other of the ports 40 or 42 will be effected.

It will be noted that no complicated sealing at the interface between the shaft 12 and the bushing 54 is required although under some circumstances it may be preferable to add simple O-rings or foam rubber seals to the bushing.

I claim:

1. A pump comprising two shafts with parallel, offset relatively rotatable axes, a pump body, an end portion of one of said shafts defining spaced ports extending radially, an end of the other of said shafts being attached coaxially to said pump body, said pump body including a rigid casing, a chambered member having flexible elastomeric webs and a bushing fixed together each in nonrotative relation to said other of said shafts, said bushing being journaled on said one shaft and having radial ports adapted to connect with said spaced ports of said one shaft, said elastomeric webs separating the interior of said chambered member into an annular series of chambers, said chambered member being retained between said bushing and inside wall surfaces of said rigid casing, an aperture in said chambered member for each of said chambers, and said aperture being connected to one of said spaced ports.

2. A pump as set forth in claim 1, said chambered member surrounding said bushing, and an end wall of said rigid casing constituting one Wall of each of said chambers.

3. A pump as set forth in claim 1, said one shaft having parallel bores extending lengthwise, one of said bores and some of said spaced ports forming a fluid inlet passage leading to said pump, and another of said bores and others of said spaced ports forming a fluid outlet passage leading from said pump.

4. A pump as set forth in claim 1, said rigid casing, chambered member and bushing being bonded together to form a unitary structure.

5. A pump as set forth in claim 1, said bushing being substantially smaller than said chambered member as measured in the direction of said axes.

6. A pump comprising a fixed shaft and a drive shaft, said shafts being parallel with one end of one of said shafts terminating close to one end of the other, one of said shafts defining an inlet passage and an outlet passage, a pump body being fixed to the other shaft, and journaled on said one end of said one shaft, said pump body including a rigid casing, a flexible elastomeric chambered member and a bushing bonded together as a unitary structure, said bushing being small and radially ported for alternate communication with said inlet and outlet passages, and said elastomeric chambered member being large and having an annular series of separate chambers each permanently connected to one of the radial ports of said bushing.

References Cited UNITED STATES PATENTS 53,609 4/1866 Hainsworth 230160 2,336,580 12/1943 Yeatman 103-117 2,882,830 4/1959 McDuflie 103-149 3,203,356 8/1965 Jepsen 103-148 3,229,643 1/1966 Roudaut 103-149 3,303,790 2/1967 McCray 103117 FRED C. MATTERN, 111., Primary Examiner.

WILBUR J. GOODLIN, Assistant Examiner. 

